This invention relates, in general, to particular phosphor admixtures which provide improved operation of flexible electroluminescent cells or lamps. Detailed descriptions of such type lamp constructions are found in issued U.S. Pat. Nos. 3,315,111 and 3,047,052, both assigned to the same assignee as the present invention. These flexible electroluminescent cells or lamps have component elements of a flexible character generally comprising a layer of an electroluminescent or field-responsive phosphor sandwiched between a pair of electrically conductive or electrode layers at least one of which is light-transmitting. When an alternating current of sufficient potential is impressed between the electrode components, the phosphor material is excited to a luminescence and the resulting light is emitted through the light-transmitting electrode layer.
A serious problem still encountered in the operation of said type electroluminescent cells or lamps is the occurrence of one or more electrical arcs which can thermally destroy the organic materials ordinarily used in the cell construction. The arcing condition is understandably enhanced at higher current densities of cell operation with shortened life being experienced along with brightness loss since arcing can cause the subsequent destruction of the cell itself. As used herein, the term "current density" signifies the milliamperes of electrical current per square inch of the light-emitting layer surface area during cell operation while the term "brightness" signifies the light output of the cell measured in foot-lamberts. Lessening of this operational problem by a means which does not produce significant brightness loss is thereby an important objective. To achieve said objective in a manner which does not further require structural modification of the existing cell design would also prove beneficial.